"Format not recognised." for m4a files

[bohning]

trafficstars

When I try to read an m4a file via

import soundfile as sf
data, samplerate = sf.read('test.m4a')

I get the following error:

soundfile.LibsndfileError: Error opening 'songs/test.m4a': Format not recognised.

Is m4a not supported? Or am I doing something wrong? The file plays just fine e.g. in VLC, was encoded by "Lavf60.3.100".